Directory Columns feature isn't working

Hi,

I’ve installed this much needed plugin and followed all instruction precisely, yet when clicking on the “Directory Columns’feature (on top-right in Edit Form screen of Gravity Forms), an empty lightbox with the title “Modify Gravity Forms Directory Columns” appears.

I Can’t add any fields to the directory view. As a result I can’t see anything on the page i’ve added the directory shortcode.

Really fiddled with it for quite a while – iv’e re-installed the plugin, deactivated all other plugins, went through all forums, etc. but no luck.

Would really appreciate your help on this!

Thanks,
Ori

http://ww.wp.xz.cn/plugins/gravity-forms-addons/